| Abstract: |
Sinusoidal obstruction syndrome (SOS), or hepatic veno-occlusive disease (VOD), is a potentially life-threatening complication that occurs primarily after myeloablative hematopoietic cell transplantation (5–10% of adults and 20–30% of children post-transplant) or high-dose chemotherapy. Damage to the sinusoidal endothelial cells and hepatocytes and ensuing hemodynamic events combine to cause progressive post-sinusoidal portal hypertension, worsening liver dysfunction, ascites, and may eventually result in multiple-organ damage and death. Risk factors may be related to the pre-transplant condition, the transplant itself, or individual patient health and characteristics. The Baltimore and modified Seattle sets are the major criteria for clinically diagnosing SOS/VOD; the European Society for Blood and Marrow Transplantation has proposed separate new diagnostic and severity grading criteria for adults and for children. Nonpharmacological preventative measures are available to reduce incidence of SOS/VOD, while symptomatic and supportive care can be employed as treatment regimens. The only approved pharmacological treatment of SOS/VOD is the oligonucleotide defibrotide, which acts on multiple pathways that effect endothelial cell homeostasis through fibrinolytic, anti-inflammatory, and protective mechanisms. Complete response and improved survival rates have been reported in adults and children, with or without multiple-organ damage, and in both allogeneic and autologous transplants. Prophylactic defibrotide for SOS/VOD had positive results in a pediatric randomized trial; a large international randomized trial is underway. Current research in ultrasound radiography with clinical and chemical biomarkers should improve our ability to prognosticate for this disease and identify it earlier in its course, and so promote timely intervention to improve treatment outcomes. © Springer Nature Switzerland AG 2022 |
